This device relates to a liquid detection sensor.
Liquid detection sensors are used to detect leakage of liquids or determine liquid levels. The liquid detectors used for this purpose include, for example, a leakage detection cable which acts as a cable type of liquid detection sensor, and a flat conductive liquid detection sensor. In a standard leakage detection cable, pulse signals are transmitted to a pair of coaxially-arranged conductors and any variation in the characteristic impedance therebetween is measured to thereby determine the leakage of liquid. Reflection or absorption of pulse signals can be measured to thereby determine a liquid level.
In a standard conductive liquid detection sensor, a voltage is applied between a plurality of conductors. Any variation in the impedance therebetween is measured (as a check on the elecrical condition of the conductors) to thereby ascertain the leakage of liquid, or the liquid level.
The transportation of liquids such as crude oil, petroleum, gasoline and kerosene, and of salts such as sulfuric acid and hydrochloric acid, from one position to another, is often done through underground pipelines, as necessary. Transporting liquids in this manner raises the problem of leakage thereof from the piping and valves.
Various systems for detecting the leakage of liquids have been proposed. They include leakage detection cables, one type of liquid detection sensors in which a cable is laid along a pipeline carrying liquid. A conductive liquid detection sensor can also be laid in the same manner on various portions of apparatus, machinery, pipes and valves, at which leakage of liquids tend to occur, or at which liquid levels are detected, to check for the leakage of liquid therefrom or determine the liquid level.
However, such conventional liquid detection sensors generally have shapes that bear no relationship to those of the containers holding the liquids being detected, such as pipelines and valves. Accordingly, it is difficult to mount these liquid detection sensors on these pipelines and valves so that they are kept in close contact therewith. Special attachment means are additionally often required. Even when such liquid detection sensors are mounted along pipelines and valves, the leakage of liquid cannot always be detected accurately because the detection sensors cannot always be mounted on suitable portions of the pipes and valves in a suitable manner.
Furthermore, in detecting certain kinds of liquid, it is necessary that corrosion-resistant attachment means are used for the liquid detection sensors, and that special care is taken.
An object of the device of this invention is to eliminate the problems encountered in conventional techniques in this field, and provide a liquid detection sensor which can be permanently deformed so that it can be suitably mounted on the container of the liquid being detected, such as a pipe or valve, and which is capable of detecting the leakage of liquid reliably.